Comparison of Morphological, Antidiabetic and Antioxidant Properties of Goji Fruits

There is a growing public interest in fruits labeled as „superfood” (functional food). A “superfood” should have a high content of bioactive substances with a positive impact on human health. Seven different cultivars of goji berry fruits (Lycium chinense Mill.) grown in north-western Poland were evaluated for its physicochemical parameters, antidiabetic and antioxidant activity, and polyphenol content. The length of 1-year-old shoots ranged from 36 cm (‘Big Lifeberry’) to 82 cm (‘Korean Big’). Cultivars from the group of Big were characterized by the biggest fruits (17.3-24.2 mm) with the greatest weight of 100 fruits (96.7­122.1 g). ‘Big Lifeberry’ contained high amounts of L-ascorbic acid (408 mg 1000/g) and provitamin A (190 mg 1000/g) and showed high antidiabetic (α-amylase IC₅₀=33.4 mg/mL; α-glucosidase IC₅₀=9.9 mg/mL) and antioxidant activity (ABTS·+ 6.21 and FRAP 5.58 mmol T/100 g). ‘Big Lifeberry’ was also characterized by a high total content of polyphenols (43.64 mg 100/g). Furthermore, the nitrite content in all the cultivars tested was at a relatively low level. Among the examined cultivars, the most attractive one concerning the consumers’ point of view of the size, weight and high content of health-promoting compounds is ‘Big Lifeberry’.